My MacBook is unable to boot. Whenever I try to boot, the spinning circle and the progress bar appears on the grey screen, but when the progress bar reaches about 40%, the computer shuts itself down. I started in Verbose Mode and tried AppleJack, and it said my harddisk needs to be repaired; but AppleJack is unable to do that. (Error Messages: "Invalid node structure" and "Incorrect number of thread records) I then tried to startup with both Recovery HD and Mac OS X Install DVD and ran the Disk Utility on both of the startups. At the First Aid tab, I selected my Hard Drive (not the Hitachi one, the Macintosh HD one) and clicked on Repair Disk. The error messages I got from Repair Disk were: Invalid volume file count Invalid node structure The volume Macintosh HD could not be verified completely. Error: Disk Utility can't repair this disk..disk, and restore your backed-up files. And, lastly, the following popup message appeared: Disk Utility stopped repairing "Macintosh HD" Disk Utility can't repair this disk. Back up as many of your files as possible, reformat the disk, and restore your backed-up files. Not being sure how to back-up my files using Disk Utility, I plugged in an external HDD to my USB port and clicked on the Restore tab in the Disk Utility. As the Source, I selected Macintosh HD and as the Destination, I selected one of the partitions I created on my external HDD. However, when I clicked on Restore, I got the following error message: Restore Failure Could not restore - Input/output error I partitioned my external HDD by creating 2 partitions formatted in Mac OS Extended Journal - GPT. Now, what can I do to save my files (and my MacBook's HardDisk)? Could anyone help me please?